Regression modeling weather and biolsolids effects on dryland wheat yields in Eastern Colorado, 2001-2012

Barbarack, K.A. and Ippolito, J.A. and McDaniel, J.P. and Hansen., N.C. and Peterson, G.A. (2013) Regression modeling weather and biolsolids effects on dryland wheat yields in Eastern Colorado, 2001-2012. Colorado State University Agricultural Experiment Station. pp. 1-20.

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Abstract

In the western Great Plains, climate dictates dryland wheat (Triticum aestivum, L) productivity. Producers use inorganic N fertilizers to improve crop yields in this region, while municipalities recycle sewage biosolids in the area. Will biosolids (from the Littleton/Englewood, CO Wastewater Treatment Plant) applications to western Great Plains dryland agroecosystems interact with weather to affect wheat production? To this end, we regressed crop yields on weather variables from 2000 through 2011 at a site about 40 km (approximately 25 miles) east of Byers, CO (Byers). We used SAS (Proc Reg) to develop several multiple regression models to predict crop yields. Our model of choice included four weather parameters for Byers wheat production. Regression variables included September and May precipitation and October and May monthly mean temperatures. Biosolids or nitrogen fertilizer application did not appear in our chosen model. We validated the wheat models using weather data and yields from the Colorado State University (CSU) Crops Testing Program from Akron, Burlington, Lamar, and Yuma, CO. According to t-tests comparing mean observed and predicted yields, the Byers model predicted yields from 2000-2011 at these locations with a +5.3% mean absolute error. A positive result of these analyses is that biosolids produced the same crop yields as commercial N fertilizer from 2001 through 2011.

Item Type:	Technical Bulletin
NWISRL Publication Number:	1479
Subjects:	Dryland crops Soil > Amendments > Fertilizer Soil > Chemistry > Nitrogen
Depositing User:	Users 6 not found.
Date Deposited:	09 Dec 2013 19:19
Last Modified:	10 Feb 2014 20:54
Item ID:	1515
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1515